bureau13

I drove the car to work last week, and it became clear that I likely won't be doing that again until the AC is functional. I've put it off long enough! There was no belt on the compressor when I got it, but I've decided I don't want to deal with trying to figure out if it's any good, or rebuilding it myself, etc. I ordered a new (well, rebuilt) compressor from Roger (I'm pretty sure it has either mineral oil or POE in it already), a new receiver/dryer, new o-rings and a new expansion valve. My thinking is to use R12, and have a shop do the evacuation/refill after I put the new parts on. Hopefully there are no leaks at that point.

I haven't been able to find any "newbie-rated" write-ups on this...apparently Dwayne never had to do this, unfortunately! Anyone know of any?

Kevin in Atlanta

I will avoid the debate on 134a vs R12. If you have rear a/c you will need a second expansion valve, remove the rear A/C console top and passenger seat to get to the rear A/C related o-rings. The rest are accessible from the engine bay and from under the car (rear a/c related as well). Do not forget the fuel cooler o-rings. As for the effort - get a couple of ounces of the correct oil, coat the o-rings and rest of it is all labor. There are a lot of o-rings.

On my 87 I had my local guys de-gas the system - none found - I then removed the expansion valves so they could flush it. Then I replaced all the o-rings, expansion valves, drier, etc. I let them pull vacuum and recharge the system That was late last year - when I tried my A/C last week it was as cold as it was last year. Very satisfying.

FredR

If you have not done so already in recent history I would also have the hoses rebuilt or replaced.

I prefer R12 but I now have to use R134a for availability reasons and it seems to work OK albeit I feel it does not get quite the same performance. That being said I try to avoid longer journeys during the summer daylight hours when temps can hit 44C and more.

Regards

Fred

bureau13

I don't have rear air. I do have a stack of o-rings but I'm not sure where they all go... Maybe there's a list in the WSM?

I'm not sure which hoses would be rebuilt? Or who would do that...

Kevin in Atlanta

Snipped from http://www.nichols.nu/tip736.htm

Here's a list of part numbers, sizes, and quantities of O-rings with rear A/C:

part number; size(mm); # front; # rear
==============================
999 707 284 40; 6.6 x 1.5; 0; 2
999 707 247 40; 7.5 x 2; 4; 3
999 707 261 40; 9.0 x 1.8; 2; 0
999 707 250 40; 10.6 x 2; 3; 1
999 707 251 40; 14.0 x 2; 3; 4
999 707 252 40; 17.0 x 2; 2; 0

And here's where they're all located:

Front A/C:

1. expansion valve (under plastic tray next to intensive washer reservoir): 2 x #251, 1 x #250, 1 x #247.
2. return line from expansion valve, middle of firewall: 1 x #252.
3. compressor fittings: 1 x #251, 1 x #250.
4. other side of return line to compressor at low side fill valve: 1 x #252.
5. heading into condenser: 1 x #250.
6. bottom of condenser heading up to receiver/drier: 1 x #247.
7. pressure and temperature switches just before receiver/drier: 2 x #261.
8. at receiver/drier: 2 x #247.

bureau13

Awesome info, thank you!

SMTCapeCod

Here's a short diag, if you aren't just going full bore/all in. And for posterity.

https://rennlist.com/forums/928-foru...eshooting.html

Because its that time of year when we'll be socked in with bazzillions of a/c threads.

bureau13

Here's a quick question...given a car that has had no belt on the compressor for at least a year, and quite possibly far longer...what is the expected result of pushing in the pin on the high pressure side fill port? I was expecting to hear nothing at all, but got a definite woosh of escaping gasses. Now, it wasn't a super strong woosh, mind you...but it definitely wooshed. Is this surprising? Just add belt and I'll be an icicle? No, I'm kidding about that...at any rate, I already have a compressor, receiver/drier and expansion valve to put on, but does this tell me anything about the integrity of the system? Or am I just having a fantasy here :-D

SteveG

Duplicate of others.

dr bob

Jeff - that little hissy sound is just a sign that everything over xx psi of refrigerant is already gone. Along an unknown quantity of oil too. You can put gauges on it to determine what xx psi might be, I guess.

It sounds like you have started gathering the pieces needed to get it going again. As you take things apart, pay very careful attention to the hoses at the compressor. If you see any grey powder in the lines, it's a sign the compressor has self-destructed, a reason to cut the belt off. It would also guide you to a full system flush and clean before bolting any new or rebuilt parts on.

bureau13

Sounds good, Dr. Bob. I will keep an eye out for that. I guess I was hoping that the fact that there was anything at all left in there after this amount of time was a good sign for the integrity of the system (i.e. do I have to rebuild the hoses, etc) as I'd love to not have to rip out more stuff than absolutely necessary.

dr bob

The cost & effort to replace seals, o-rings and hard parts, then evacuate, charge and then sniff for leaks... Is only slightly higher if you include getting the known-weepy hose rebuilt as part of the process. Each and every spring, folks ask for that one leaky o-ring to be replaced, then find out days later that the charge is gone and they need to go in and replace the next one. Rinse, repeat, until every component is new. That process would be ok for you of course, with no worries about cost or having it completed this year. Plus it so seldom gets hot or humid where you live, you probably wouldn't use the system much anyway. Oh, those annual visitors looking for the one magic ring... Annual visitors.

Do It Once, Do It Right, Do It Like You Mean It.

bureau13

Yes, that makes sense. I was just reading about one of the hoses being a major PITA to get to...I think there are three total, right?

I'll probably do it. I'm slow enough on the replacement of various things that I can almost undoubtedly get those hoses rebuilt in the time it takes me to get everything else back together...I guess just your standard AC shop would do it?

Still though....wouldn't you expect, at this age and after sitting for over a year, that there would be no pressure left? I was just not expecting any hiss at all.

Another question...after further poking around in my box o' stuff...I got a package of green o-rings, and a package of black. Aren't the green ones for R-134a? Or can they be used for either? As for the black ones, I think maybe those were just what came with the compressor itself...perhaps I have green ones to use instead, as well as for other places (more green ones, and different sizes).

bureau13

OK the green o-rings will work for everything, found that info.

Regarding this barrier hose rebuild, there are two, yes (no rear AC)? Or 3? I saw a mention of 3 somewhere, but Griffiths sells just two that I can see. Not sure how much it costs to have a shop rebuild them...it would be about $260 to buy the pair of them from Griffiths, so if it's significantly cheaper to rebuild, that's probably what I'll do.

I saw some talk about how much of a pain it is to get them (or at least one of them) out. Is this for all model years? Is this yet another task I need to line up for when I replace motor mounts? I haven't found much good info on the removal and replacement of these hoses.

ammonman

When I did my major refurb I had a local shop rebuild all the A/C hoses for my front and rear systems except the one that is near impossible to remove with the engine in the car . Cost for new barrier hose, ferrules and labor was about $300 all in. If/when the engine comes out I'll do the last line.

Mike